<template>
  <div class="article-container">
    <!-- 导航栏 -->
    <van-nav-bar
      class="page-nav-bar"
      left-arrow
      title="黑马头条"
      @click-left="$router.back()"
    ></van-nav-bar>
    <!-- /导航栏 -->

    <div class="main-wrap">
      <!-- 加载中 -->
      <div class="loading-wrap" v-if="loading">
        <van-loading color="#3296fa" vertical>加载中</van-loading>
      </div>
      <!-- /加载中 -->

      <!-- 加载完成-文章详情 -->
      <div class="article-detail" v-else-if="article.title">
        <!-- 文章标题 -->
        <h1 class="article-title">{{ article.title }}</h1>
        <!-- /文章标题 -->

        <!-- 用户信息 -->
        <van-cell class="user-info" center :border="false">
          <van-image
            class="avatar"
            slot="icon"
            round
            fit="cover"
            :src="article.aut_photo"
          />
          <div slot="title" class="user-name">{{ article.aut_name }}</div>
          <div slot="label" class="publish-date">
            {{ article.pubdate | relativeTime }}
          </div>

          <!--
            模板中的 $event 是事件参数
            当我们传递给子组件的数据既要使用还要修改。
              传递：props
                :isFollowed="article.is_followed"
              修改：自定义事件
                @update-followed="article.is_followed = $event"
            简写方式：在组件上使用 v-model
              value="article.is_followed"
              @input="article.is_followed = $event"

            如果需要修改 v-model 的规则名称，可以通过子组件的 model 属性来配置修改

            一个组件上只能使用一次 v-model，
            如果有多个数据需要实现类似于 v-model 的效果，咋办？
            可以使用属性的 .sync 修饰符。
           -->
          <follow-user
            class="follow-btn"
            v-model="article.is_followed"
            :authorId="article.aut_id"
          ></follow-user>
        </van-cell>
        <!-- /用户信息 -->

        <!-- 文章内容 -->
        <div
          class="article-content markdown-body"
          v-html="article.content"
          ref="articleContentRef"
        ></div>
        <van-divider>正文结束</van-divider>

        <!-- 评论区域 -->
        <comment-list
          :source="article.art_id"
          :list="commentList"
          @onloadSuccess="totalCommentCount = $event.total_count"
          @reply-click="onReplyClick"
        />

        <!-- 底部区域 -->
        <div class="article-bottom">
          <van-button
            class="comment-btn"
            type="default"
            round
            size="small"
            @click="isPostCommentShow = true"
          >
            写评论
          </van-button>
          <van-icon name="comment-o" :badge="totalCommentCount" color="#777" />

          <!-- 文章收藏 -->
          <collect-article
            v-model="article.is_collected"
            :articleId="article.art_id"
          />

          <!-- 文章点赞 -->
          <like-article
            v-model="article.attitude"
            :articleId="article.art_id"
          />

          <van-icon name="share" color="#777"></van-icon>
        </div>
        <!-- /底部区域 -->

        <!-- 发布评论弹出层 -->
        <van-popup v-model="isPostCommentShow" position="bottom">
          <comment-post :target="article.art_id" @postSuccess="addComment" />
        </van-popup>
      </div>
      <!-- /加载完成-文章详情 -->

      <!-- 加载失败：404 -->
      <div class="error-wrap" v-else-if="errStatus === 404">
        <van-icon name="failure" />
        <p class="text">该资源不存在或已删除！</p>
      </div>
      <!-- /加载失败：404 -->

      <!-- 加载失败：其它未知错误（例如网络原因或服务端异常） -->
      <div class="error-wrap" v-else>
        <van-icon name="failure" />
        <p class="text">内容加载失败！</p>
        <van-button class="retry-btn" @click="loadArticle">点击重试</van-button>
      </div>
      <!-- /加载失败：其它未知错误（例如网络原因或服务端异常） -->
    </div>

    <!-- 回复评论弹出层 -->
    <van-popup
      v-model="isReplyCommentShow"
      position="bottom"
      style="height:100%"
    >
      <comment-reply
        v-if="isReplyCommentShow"
        :comment="currentComment"
        @close="isReplyCommentShow = false"
      />
    </van-popup>
  </div>
</template>

<script>
import { ImagePreview } from 'vant'
import { getArticleById } from '@/api/article'

import FollowUser from '@/components/follow-user'
import CollectArticle from '@/components/collect-article'
import LikeArticle from '@/components/like-article'

import CommentList from './components/CommentList'
import CommentPost from './components/CommentPost'
import CommentReply from './components/CommentReply'

export default {
  name: 'ArticleIndex',
  components: {
    FollowUser,
    CollectArticle,
    LikeArticle,
    CommentList,
    CommentPost,
    CommentReply
  },
  // 给所有的后代组件提供数据
  provide: function() {
    return {
      articleId: this.articleId
    }
  },
  props: {
    articleId: {
      type: [Number, String, Object],
      required: true
    }
  },
  data() {
    return {
      article: {}, // 文章详情内容
      loading: false, // 控制loading状态显示
      errStatus: 0, // 控制错误状态码
      totalCommentCount: 0, // 评论总条数
      isPostCommentShow: false, // 控制发布评论弹出层
      isReplyCommentShow: false, // 控制回复评论弹出层
      commentList: [], // 评论列表
      currentComment: {} // 当前评论数据内容
    }
  },
  computed: {},
  watch: {},
  created() {
    this.loadArticle()
  },
  mounted() {},
  methods: {
    async loadArticle() {
      this.loading = true
      try {
        const { data: res } = await getArticleById(this.articleId)

        // 失败测试
        // if (Math.random() > 0.5) {
        //   JSON.parse('xiaozhang test')
        // }

        this.article = res.data

        // 在数据获取成功后 处理图片预览
        setTimeout(() => {
          this.imagesPreview()
        }, 0)
      } catch (error) {
        if (error.response && error.response.status === 404) {
          this.errStatus = 404
        }
      }
      // 无论成功失败 加载完成后都需要关闭loading状态
      this.loading = false
    },
    imagesPreview() {
      // 拿到整个文章详情的DOM容器
      const articleContentRef = this.$refs.articleContentRef
      // 拿到所有的img元素
      const imgAll = articleContentRef.querySelectorAll('img')
      // console.log(imgAll)
      const imgURL = []
      imgAll.forEach((item, index) => {
        // 遍历img元素,拿到所有的图片地址
        imgURL.push(item.src)

        // 给所有的img图片绑定点击事件
        item.onclick = () => {
          ImagePreview({
            images: imgURL,
            startPosition: index
          })
        }
      })
      // console.log(imgURL)
    },
    addComment(data) {
      // 关闭评论弹层
      this.isPostCommentShow = false
      // 追加最新评论
      this.commentList.unshift(data.new_obj)
    },
    onReplyClick(comment) {
      // console.log(comment)
      this.currentComment = comment
      this.isReplyCommentShow = true
    }
  }
}
</script>

<style scoped lang="less">
@import '~@/styles/github-markdown.css';

.article-container {
  .main-wrap {
    position: fixed;
    left: 0;
    right: 0;
    top: 92px;
    bottom: 88px;
    overflow-y: scroll;
    background-color: #fff;
  }
  .article-detail {
    .article-title {
      font-size: 40px;
      padding: 50px 32px;
      margin: 0;
      color: #3a3a3a;
    }

    .user-info {
      padding: 0 32px;
      .avatar {
        width: 70px;
        height: 70px;
        margin-right: 17px;
      }
      .van-cell__label {
        margin-top: 0;
      }
      .user-name {
        font-size: 24px;
        color: #3a3a3a;
      }
      .publish-date {
        font-size: 23px;
        color: #b7b7b7;
      }
      .follow-btn {
        width: 170px;
        height: 58px;
      }
    }

    .article-content {
      padding: 55px 32px;
      /deep/ p {
        text-align: justify;
      }
    }
  }

  .loading-wrap {
    padding: 200px 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #fff;
  }

  .error-wrap {
    padding: 200px 32px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: #fff;
    .van-icon {
      font-size: 122px;
      color: #b4b4b4;
    }
    .text {
      font-size: 30px;
      color: #666666;
      margin: 33px 0 46px;
    }
    .retry-btn {
      width: 280px;
      height: 70px;
      line-height: 70px;
      border: 1px solid #c3c3c3;
      font-size: 30px;
      color: #666666;
    }
  }

  .article-bottom {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    justify-content: space-around;
    align-items: center;
    box-sizing: border-box;
    height: 88px;
    border-top: 1px solid #d8d8d8;
    background-color: #fff;
    .comment-btn {
      width: 282px;
      height: 46px;
      border: 2px solid #eeeeee;
      font-size: 30px;
      line-height: 46px;
      color: #a7a7a7;
    }
    .van-icon {
      font-size: 40px;
      .van-info {
        font-size: 16px;
        background-color: #e22829;
      }
    }
  }
}
</style>
